Switch for electric circuits



A.GRAF. SWITCH FOR ELECTRIC CIRCUITS APPLICATION FILED NOV- 28,1919.

Patentd Oct. 4, 1921.

FI A.

UNITED STATES PATENT OFFICE...

SWITCH FOR ELECTRIC CIRQUITS.

Specification 01' Letters Patent.

Patented Oct. 4;, 1921.

, Application filed November 28, 1919. Serial No. 341,227.

To all whom it may concern:

Be it known that I, ALEXANDER GRAF, of Libau, Curland, Russia, residing at 20 \Valdseestrasse, Berlin Hermsdor'f, Germany, have invented certain new and useful Improvements in Switches for Electric Circuits, of which the following is a specification.

The invention relates to a new switch for electrical installations, as for example electric light and the like, which differs greatly from, and is much superior to, known devices of this kind inasmuch as it consists of a comparatively small number of separate parts which may be joined to each other or assembled without the use of screws.

It is a well known fact that in types of switches employed for the pur ose for which the new switch is designe a large number of screws is required. Thus all incoming and outgoing wires have to be clamped fast in their holes by screws. 'When subjected to vibration these screws, which have to be made small on account of limited space, easily get loose and revent the proper working of the switc Bersides, they can easily be lost and are troublesome to handle and cause loss of pieces now used to establish connections between diiferent contacts in the switch decreases in the course of time, or these pieces preak off altogether making the switch useess.

The object of the invention is to remove these drawbacks. This is accomplished by inserting the wires connected to the switch in metal pieces that are embedded in a plate of insulating material. Connections are established in the known manner between corresponding wires in accordance with circuit requirements by a movable metallic bridging piece. Thls bridging piece is pressed down upon the parts or contacts beneath as firmly as necessary by a spring. The wires connected to the switch are held in position without employing screws by a clamping ring which is forced down on the periphery.

of the base plate consisting of insulating material and then fixes the ends of the wires. In a modified form of the switch this clamp-- ing ring may be arranged to be pushed over the edges of the plate and furnished with an external thread. If a corresponding internal thread is then provided in the switchbridgin time. And the elasticity of the bridging.

cover the clamping ring may be made to serve for the additional purpose of holding the cover.

The connecting or bridging piece is moved from contact to contact in the well known manner by a revoluble shaft, upon a four cornered section of which the bridging piece is fixed, i. e. the part of the shaft that is inside the hole of the brid ing piece is made rectangular or square. y a spring situated between the switch-cover and the piece this latter is pushed down with a equate pressure against the switch base. To render the positions in which the bridging piece establishes connections between contacts perceptible to the touch of the person using the switch, and to secure a certain locking action in these positions, the contacts are provided at the top with furrows into which the rubbing portions of the bridging piece. are adapted to fit. The shaft or spindle carrying the bridging piece is journaled in the insulating base and may protrude through the base and be held in position by a suitable fixing means beneath the base, or it may be let into the base without passing through it.

Two ways of carrying out the invention are shown in the drawing in which- Figure 1 is a vertical section through one type of the switch,

Fig. 2 a section through Fig. 1 on the line IIII,

Fig. 3 a section through Fig. 1 on the l1ne III-III and Fig. 4 a vertical section through a second type of switch.

The switch consists of a base plate 1 in which metal parts or contacts 2 are embedded or inserted in suitable channels. The metal parts 2 have holes running lengthwise in which the wires 3 are inserted. The outer ends of the wires are held fast and the wires thus kept in position by a clamping ring 4 which is pushed over the rim of the base plate 1. Connections between corresponding contacts 2 are established by a metallic bridging piece 5. This bridge 5 is mounted on the four-cornered portion of the shaft 6 which is adapted to be turned by the handle 7 The shaft or spindle Gpasses through the switch cover 8 which may be held in position in the well known manner by the handle 7. Between the inner surface of the cover 8 and the upper side of the brid e 5 a spring 9 is placed which presses't e bridge down against the base.

The top of each part 2 is shaped as shown in Fig. 3, i. c. it is formed with a furrow in WhlCh the bridge clenches. The spindle 6 is journaled in the base-plate l and is held in any suitable manner, as for example by a nut 10 or a bur.

In the type of switch shown in Fig. 4 the clamping rin 4 is slipped on f om below and provide with an external thread 11. Onto this thread a corresponding female screw in the cover may be screwed. If the switch is made in this manner the spindle 6 need not ass through the baseplate. It'will be su cient to.lodge it deep enough in the base to secure a 'sufliciently stron bearing. It may also be mentioned that in this type of switch the cover 8 is not held in place by the handle 7.

I claim:

' 1. A switch for electric circuits comprising a base of insulating material with channels therein, metal pieces with holes in the directions of their lengths for the wires of the circuits, said metal pieces being inserted in the said channels, and a bridging piece for establishing connections between the said metal pieces.

2. A switch for electric circuits comprisin v a base of insulating material with channe s therein, metal pieces with holes infthe directions of their lengths for the wires of the circuits, said metal pieces being inserted in the said channels, a bridging piece for establishing connections between the said metal pieces, and a clamping ring fitting over the (rim of the said base for holding the said wires in position.

3. A switch for electric circuits comprisin a base of insulating material with chanexternal thread on the clamping ring, and

a switch cover with a female thread screwed onto the thread of the clamping ring;

4. A switch for electric circuits comprisin a base of insulating material with channe s therein, metal ieces with holes in the directions of their engths for the wires of the circuits, said metal pieces being inserted in the said channels, a bridging piece for establishing connections between the said metal pieces, a spindle fixed in the said base,

a handle on the said spindle, and a switch cover held in position'b the saidhandle.

In testimony whereo I have signed this specification in the presence of two witnesses. v

' ALEXANDER GRAF. Witnesses: V p

MILLER DOOKBURN,

' WALT naVnsK. 

